Railway car coupler

ABSTRACT

A knuckle-type railway car coupler having a modified 10A coupler contour wherein the pulling face of its pivoted knuckle is offset approximately five-sixtyfourths inch closer to the front face of the coupler head, and the heel and adjacent front face portions of the knuckle are relieved and contoured along a smooth compound convex curve formed by several radii to provide a tightened coupler contour of substantially reduced slack compared to the standard 10A contour. The knuckle further has the portion of the inner side wall of its tail portion adjacent and extending rearwardly from its throat section relieved along a smooth concave curve of substantial radius to prevent binding between couplers during uncoupling.

[ Dec. 24, 1974 [5 RAILWAY cAR COUPLER [75] Inventor: William J. Metzger, East Cleveland,

Ohio.

[73] Assignee: Midland Ross Corporation,

Cleveland, Ohio [22] Filed: Aug. 6, 1973 [21] Appl. No.: 385,747

[52] US. Cl 213/151, 213/109, 213/152 Primary Examiner-M. Henson Wood, Jr. Assistant ExaminerGene A. Church I Attorney, Agent, or Firm-Henry Kozak [57] ABSTRACT A knuckle-type railwav car coupler having a modified 10A coupler contour wherein the pulling face of its pivoted knuckle is offset approximately fivesixtyfourths inch closer to the front face of the coupler head, and the heel and adjacent front face portions of the knuckle are relieved and contoured along a smooth compound convex curve formed by several radii to provide a tightened coupler contour of substantially reduced slack compared to the standard 10A contour. The knuckle further has the portion of the inner side wall of its 'tail portion adjacent and extending rearwardly from its throat section relieved along a smooth concave curve of substantial radius to prevent binding between couplers during uncoupling.

10 Claims, 6 Drawing Figures RAILWAY CAR COUPLER BACKGROUND OF THE INVENTION This invention relates in general to knuckle-type railway car couplers and, more particularly, to the contour of their opposed mating surfaces.

Most of the car couplers in interchange service on railroads in the United States are of the standard E type which have the standard A coupler contour established by the American Association of Railroads (A.A.R. The 10A contour is designed to initially provide sufficient free slack between mated new couplers, amounting to twenty-five thirtyseconds inch, to enable them to meet the standard requirements as to both horizontal and vertical angling therebetween. These requirements specify at least 11 of horizontal angling displacement and 3 57 of vertical angling displacement for new couplers, and at least 13 30 and 4 45, respectively, for couplers after they have been seated or worn in three thirty-seconds inch, as measured along the longitudinal center line of the coupler,'by their use in service.

After a coupler has been initially placed in service,

there is a certain amount of preliminary wearing off of the high spots and surface roughness on all bearing surfaces during which time the coupler parts become seated in place. This seating in of the coupler parts is accompanied by an opening or stretching of the coupler contour which, in turn, results in an increase in the amount of free slack between the mated couplers and also an increase in the amount of horizontal and vertical angling that can take place therebetween. Since the rate of wear of the couplers is more or less directly proportional to the amount of free slack, the desired condition would be for the couplers to have the least possible amount of free slack therebetween while still retaining the required amount of horizontal and vertical angling. Such coupler slack reduction and wear reduction is further desirable for the added reason that it operates to prolong the effective life of the couplers, as determined by their having exceeded the worn limit for safety against the danger of the mated couplers slipping apart with their knuckles closed and locked.

The standard 10A coupler contour, which has an initial slack of twenty-five thirty-seconds inch, provided an eleven'slxty-fourths inch or approximate 18 percent reduction in slack from the 61/64 inch slack of the previous standard No. 10 coupler contour. However, despite this sizeable reduction in slack, the initial 25/32 inch slack of the 10A coupler contour nevertheless is still large enough to cause a relatively high rate of coupler wear and resultant contour opening and stretching such as undesirably foreshortens the effective service life of the coupler.

DESCRIPTION OF THE PRIOR ART There have been prior proposals for modifying the construction of knuckle-type couplers to provide a socalled tightened coupler contour operative to reduce the free slack between mated couplers while at the same time maintaining the required standard horizontal and vertical angling therebetween. These prior proposed modifications, however, while they may have proven acceptable for incorporation into the then existing standard coupler construction without interfering with the established operational requirements therefor,

ing of the upper and lower portions of the front face of the coupler knuckle at an angle of 4 40' to the vertical in order to permit the same amount of vertical angling between the so modified couplers as the then standard A.A.R. coupler having the No. 10 contour. Theaddition, however, of such a metal layer around the indicated thickness of five-sixteenths inch or so to the knuckle pulling face of a coupler having the present standard 10A contour to reduce the slack would result in a wholly inoperative coupler incapable of even coupling together with another coupler of similar modified construction. Moreover, even though the added layer of metal on theknuckle pulling face of a 10A contour coupler beonly of a nominal thickness, e.g., as little as three thirty-seconds inch, such a contour modification would not, of itself, result in a coupler that would meet all the standard operating requirements therefor. Thus, the knuckles of such modified couplers would bind with one another and restrict uncouplingof the couplers when the knuckle of only one of them is unlocked and free to swing open. In addition, such modified couplers would have only a small bearing area when in buffed position such as would result in undesirable rapid wear of their buffing surfaces and loosening or opening of the coupler contours.

A particular disadvantage would result, moreover, in the case where the additional layer of metal is added to the front face of the'coupler head. This would cause a change in the distance, longitudinally of the coupler, from the front face of the knuckle to the front face of the coupler head, as compared to that of a standard 10A coupler contour. Thus, such a modified contour coupler would mismatch with existing standard 10A contour couplers since, during buffing operations therebetween, there would be buffing interengagement between only one of the two sets of opposed knuckle and coupler buffing interfaces, i.e., between only the front buffing face of the knuckle on the 10A contour coupler with the added layer front face of the coupler head of the modified coupler. Accordingly, the buffing forces would be concentrated against the added layer front face of the modified coupler head, resulting in an increased rate of wear thereof as compared to that which occurs in so-called matched couplers wherein the distance between their respective knuckle and coupler head front faces are the same, i.e., matched, so that both sets of their opposed knuckle andcoupler head buffing interfaces engage with one another during buffing operations to thereby distribute the buffing forces over both these engaged surfaces and so reduce the unit surface loading thereof.

US. Pat. No. 2,007,45 l Kinne, discloses the tightening of the contour of a coupler having the then standard Na. 10 coupler contour by the bodily shifting of the knuckle both rearwardly toward the coupler head and laterally inward toward the guard arm through the relocation of the knuckle pivot pin hole in either the knuckle or in the coupler head. This shifting of the knuckle relative to the coupler head is designed to compensate for loosening or stretching of the coupler contour, due to seating or wearing in of the coupler parts, and in such way prolong the effective life of the coupler. Such an inward shifting, however, of the knuckle of a coupler having the present standard No. A coupler contour would result in a coupler which would not meet the standard minimum requirements for horizontal angling between mated couplers. Also, because of the change in the distance between the front faces of the knuckle and coupler head of such a modified type coupler compared to a standard 10A contour coupler, the modified coupler would mismatch with existing couplers having standard 10A contours in the same way as described hereinabove in connection with couplers having an additional layer of metal added to their coupler head front faces.

US. Pat. No. 2,178,062, Bazeley, discloses both a slack-free coupler known as the tight-lock coupler and a reduced slack coupler referred to as a semi-tight coupler, both of which couplers'have tightened contours compared to a standard 10A coupler contour. However, neither of'these modified couplers provide in themselves any horizontal or vertical angling thereof to the degree required for couplers having the standard 10A contour.

SUMMARY OF THE INVENTION Briefly stated, in accordance with one aspect of the invention, the standard 10A contour of a car coupler such as the standard E coupler, for example, is modifled by offsetting the pulling face of the coupler knuckle a distance of approximately five sixty-fourths inch closer to the front face of the coupler, as measured along the longitudinal center line of the coupler, and relieving and contouring the heel and immediately adjacent front wall portions of the coupler knuckle along a smooth compound convex curve formed by several radii. By such modification, a coupler contour is provided which not only is of materially tightened character effective to reduce the free slack between and wear rate of mated couplers while at the same time maintaining their horizontal angling capabilities above the acceptable minimum required limits for couplers with standard 10A contours, and also maintaining the standard distance relationship between the front faces of the knuckle and coupler head. The modified coupler contour also assures a substantial bearing area between the buffing surfaces of the couplers when in buffed position such as to further minimize the wear rate thereof.

According to a further aspect of the invention, the I portion of the inner side wall of the knuckle tail portion adjacent and extending rearwardly from its throat section is relieved and contoured along a smooth concave curve of relatively large radius to provide during an uncoupling operation, clearance for free withdrawal and disengagement from the coupler, while its knuckle is locked in closed position, of the unlocked knuckle of an opposing mating coupler.

It is an object of the invention, therefore, to provide a knuckle-type car coupler having a standard 10A coupler contour modified to provide a tightened contour of reduced free slack while the amount of horizontal and vertical angling of the coupler is maintained within acceptable standard amounts.

A further object of the invention is to provide a knuckle type car coupler of thereduced slack character referred to above and having a substantial bearing area of its buffing surfaces against those of another coupler when in buffed position therewith as well as when horizontally angled relative thereto.

A still further object of the invention is to provide a knuckle-type car coupler of the reduced slack character referred toabove and which retains the same distance relationship between the front faces of its knuckle and coupler head as the standard 10A contour coupler so as to thereby match and couple with all type couplers having such standard 10A contours.

Another object of the invention is to provide a knuckle-type car coupler of the reduced slack character referred to above and in which the only coupler contour changes thereof over the standard 10A coupler contour are all inthe knuckle contour itself.

Still another object of the invention is to provide a knuclde-type car coupler of the reduced slack character referred to above which will not bind within and will freely withdraw and uncouple from another coupler having its own knuckle locked in closed position.

Further objects and advantages of the invention will be apparent from the following description of species thereof taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a fragmentary top plan view of a coupler comprising the invention embodying the novel coupler contour thereof, the dotted lines indicating the present standard A.A.R. 10A contour.

FIG. 2 is a fragmentary top plan view of a pair of coupled couplers according to the invention showing the relation therebetween in draft.

FIG. 3 is a view similar to FIG. 2 but showing the relation between the couplers in buff.

FIG. 4 is a view similar to FIG. 2 but showing the relation between the'couplers in their maximum horizontally angled coupled position.

FIG. 5 is a fragmentary top plan view of two opposing couplers according to the invention shown during the coupling together thereof while in horizontally angled relative position, and I FIG. 6 is a vertical section taken on the line 66 of FIG. 3 and showing the couplers in maximum vertically angled relative position.

Referring to FlG l .of the drawings, the coupler according to the invention embodies a coupler contour 10, shown in solid lines, which comprises a modified form of the present standard A.A.R. (American Association of Railroads) No. 10A contour shown in dotted lines at 12. The coupler itself may be of' any type that presently employs the standard 10A contour such as, for example, the standard A.A.R. Type E coupler. Such couplers are conventionally comprised of a head or body portion 14 having ears 16 on which a knuckle 18 is pivotally mounted by means of a pivot pin 20.

As is well known in the art, the coupler contour 10, like that of most all couplers, is constituted by the contour line or configuration of its coupling interface with a mating coupler, and it is formed in part by the contour of the front or buffing face portion 22 and the inner side face 24 of the guard ai'm portion 26 of the coupler head 14, and in part by the contour of the nose 28, front face 30 and heel portion 32 of the knuckle 18 when in its closed or coupling position and also by the throat portion 34 and adjacent inner side face 36 of the tail portion 38 of the closed knuckle. Also as is customary, the coupler contour is laid off from the longitudinal center line XX of the coupler and the transverse construction line Y-Y which extends at 90 to the center line XX. As in the case of the standard 10A coupler contour 12, the contour 10 of the coupler according to the invention is laid off with the transversely extending flat end or nose 40 of the coupler guard arm 26 coincident with the transverse construction line YY.

The knuckle nose or hook portion 28 of the coupler according to the invention, like that of the knuckles of couplers having the standard 10A coupler contour, is formed with a reversely curved inward or pulling face 42 constituted by a convex outer arcuate portion 44 and a concave inner arcuate portion 46 struck on oppositely disposed 1 inch radii on centers located approximately equidistant from and on opposite sides of the longitudinal center line XX when the knuckle is in its closed position, and joined by a short tangent mid section 48. The tangent mid-section 48 is more or less centered about the longitudinal center line XX of the coupler when the knuckle 28 is locked in its closed position in the coupler head 14 as shown in H0. 1, and it faces inwardly toward the throat 34 of the knuckle in more or less opposing relation thereto and extends along a straight line 8-8 disposed at an angle of to the longitudinal center line XX of the coupler. The tangent line 8-8 passes through the intersection point P of the longitudinal center line XX with a transversely extending coupling or base line AA parallel to the transverse construction line Y-Y. As shown, the concave inner arcuate portion 46 of the pulling face 42 of the knuckle 18 joins with a tangent throat section 34 which approximately coincides or meets with the curvature of the pivot ears or lugs 16 on the coupler head 14.

In a coupler with a standard 10A coupler contour, the established coupling line A'-A' therefor is offset three thirty-seconds inch toward the front or buffing face 22 of the coupler head 14 from the transverse construction line Y-Y, and its reversely curved pulling face 42' is formed by the convex and concave 1 inch radii arcuate portions 44' and 46' corresponding to the arcuate portions 44 and 46 of the coupler contour 10 according to the invention and joined by the tangential mid-section 48' which passes through the intersection point P of the coupling line A'--A' with the longitudinal axis XX at an angle of 30 degrees to the coupling line. As mentioned previously, couplers with such standard 10A contours 12 have 25/32 inch free slack between mated couplers which permits them .to angle up I theless is still undesirably excessive since it results in a relatively high rate of wear for the interengaging bearing surfaces of the couplers-and corresponding foreshortened service life therefor as determined by their coupler contours having opened or loosened beyond the established worn limit.

In accordance with the invention, the knuckle pulling face portion 42 of the contour 10 of a coupler comprising the invention is located in a position, when the knuckle 18 is locked in its closed position as shown in FIG. 1, which is offset relative to the position of the pulling face 42' of a standard 10A coupler contour 12 a distance of approximately five sixty-fourths inch closer to the opposing front or buffing face 22 of the coupler head 14, as measured along the longitudinal center line XX of the coupler. In other words, the coupling line AA and center point P of the pulling face 42 is located a distance, measured along the longitudinal center line XX, approximately eleven sixtyfourths inch away from the transverse construction line Y--Y and toward the buffing face 22 of the coupler head 14, or five sixty-fourths inch more than the corresponding 3/32 inch spacing from the construction line Y-Y of the coupling line A' A and pulling face center point P of the standard 10A coupler contour 12. By thus locating the knuckle pulling face 42 in such appreciably closer, i.e., five sixty-fourths inch closer relation to the coupler head buffing face 22, the coupler con tour is tightened a substantial amount and the free slack between mated couplers is reduced to' fiveeighths inch from the 25/32 inch free slack present between mated couplers having standard 10A contours. This represents approximately a 20-percent reduction in free slack and a consequent material reduction in the wear rate of the coupler.

The reduction in coupler free slack which is afforded by the use of couplers according to the invention having the tightened contour 10 is illustrated in FIG. 2 which shows the relative position of a mated'pair of such couplers in pulled or draft position. It will be apparent that the distance D between the respective opposing buffing faces 22 and knuckle front faces 30 of such mated couplers when in draft position is appreciably less, i.e., approximately five sixty-fourths inch less, than the corresponding distance D between the buffing faces 22and knucklefront faces 30, shown in dotted lines, of couplers provided with the standard 10A coupler contour. The amount of this difference in the distances D and D corresponds to the five sixty-fourths inch closer positioning of the knuckle pulling face 42 of a' coupler according to the invention to its buffing face 22 than that of the knuckle pulling face 42' of a standard 10A contour coupler.

To enable mated couplers having the tightened contour 10 according to the invention to horizontally angle, after seating, at least the accepted minimum required amount of at least 11 for unseated couplers, and also to provide substantial bearing surface therebetween when in buffed position as well as during horizontal angular displacement, the heel 32 and immediately adjacent portion of the front face 30 of the knuckle is relieved from the contour of the standard 10A coupler contour, and contoured along a smooth compound convex curve 50 formed by several radii. For example, the compound curve 50 may be formed by arcs struck with successive radii of about 3 inches,

10 inches, and 1%. inches leading from and tangent to the front face 30 of the knuckle and extending toward and around the heel 32 thereof and joining in a smooth continuous curve with the slightly convexly curving outer side face 52 of the knuckle. The extent of the relieving of the knuckle heel and adjacent front faceportion afforded by the-compound curve contour 50, from amount after only a relatively short period of service.

The substantial bearing surface thus provided between the knuckle front faces 30 and the opposing coupler head buffing faces 22 of two mated couplers according to the invention will also be present where such a coupler is coupled with and in buffed relation to a coupler having either the standard 10A contour, the Type F Interlocking contour, or the A.A.R. Tightlock contour.

FIG. 4 shows the substantial bearing surface which is provided between mated couplers according to the invention by the relieved compound curve portion 50 of the knuckle front face 30 and heel 32 of the couplers when they are in their maximum horizontally angled position relative to one another. This position is possible after the couplers have been seated eleven sixtyfourths inch, and amounts to approximately 12 30 of horizontal angular displacement. As shown in FIG. 4, the couplers engage with one another along an appreciable length L of their respective contours 10 between the points G and H. This extent L of bearing surface between the couplers when in maximum horizontally angled position is appreciably greater than that which is presentbetween couplers having standard 10A coupler contours 12. As a consequence, the rate of wear of the coupler bearing surfaces from the forces applied thereto while the couplers are in horizontally angled position is substantially less than that which takes place with standard 10A contour couplers. The substantial bearing surface provided between the relieved compound curve portion 50 of the knuckle 18 and the opposing coupler head buffing face 22 of mated couplers according to the invention when in their maximum horizontally angled position relative to one another will also be present where such a coupler is coupled with and in maximum horizontally angled position relative to a coupler having either the standard 10A contour, the Type F Interlocking contour, or the A.A.R. Tightlock contour.

Because of the relieving of the heel 32 and adjacent front face portion 30 of the knuckle 18 to formthe compound curve contour portion 50, couplers according to the invention are capable of as much as 1 1 10 of horizontal angling after the comparatively short period of time required in service to effect a 3/32 inch seating of the couplers, and up to 12 30 of horizontal angling, as shown in FIG. 4, after they have been seated eleven sixty-fourths inch. Thus, the modified contour couplers of the invention have, after 3/32 inch seating, a horizontal angling capability, i.e., 11 10', which is slightly more than the 1 1 maximum horizontal angular displacement of unseated, or new couplers having the present standard 10A contour. Assumedly, of 11 if horizontal angular displacement is sufficient to meet present service requirements with a non-seated standard 10A contour coupler then, because this amount of horizontal angling displacement is exceeded by the modified contour coupler according to the invention after the short service period required to seat the coupler three thirty-seconds inch, such modified contour couplers therefore should not, as a practical matter, present any difficulty with respect to their meeting the horizontal angling requirements likely to be encountered in service.

Besides meeting for all practical purposes the standard horizontal angling service requirements when coupled with each other after seating, couplers embodying the invention, when coupled in interchange service with other standard type couplers will provide, after seating, substantially as much horizontal angling as an unseated standard 10A contour coupler will provide under the same interchange service conditions. Thus, when coupled with and angled toward the knuckle side of a standard 10A contour coupler, a tightened contour coupler comprising the invention will provide, after 3/32 inch seating, up to approximately 1 1 15' of horizontal angling and, when angled toward the guard arm side, it will provide up to 12 of horizontal angling. Since both these horizontal angling displacements exceed the 1 lmaximum horizontal angling possible between mated but unseated couplers of standard 10A coupler contour, the modified contour couplers of the invention, for the same reasons mentioned hereinabove in connection with the horizontal angling capabilities of couplers comprising the invention when mated to each other, should not as a practical matter present any difficulty with respect to their meeting the standard horizontal angling requirements in the case where they are coupled to a standard 10A contour coupler. Likewise, when coupled to a standard Type F Interlocking coupler, the modified contour coupler according to the invention will provide, after 3/ 32 inch seating, up to 8 15' of horizontal angling when angled toward the knuckle side of the F coupler and up to 7 45' of horizontal angling when angled toward the guard arm side of the F coupler. These horizontal angling displacements in this coupling situation substantially correspond. to the 8 maximum horizontal angling displacement of a standard 10A contour coupler when coupled with a Type F Interlocking coupler, the slight difference therebetween in any case being so small as to be insignificant in view of the additional horizontal angling capability normally provided for the Type F Interlocking coupler by its support mounting in the car.

From the above explanation of its horizontal angling capabilities, it will be evident that the modified 10A contour couplers according to the invention meet substantially all the standard horizontal angling requirements for the present standard 10A contour coupler both when coupled to each other as well as when coupled in interchange service with other type couplers having such 10A contours.

For the coupler according to the invention to be properly operative and capable of satisfactorily performing all the required service operations, the contour of that portion 36 of the inner side face of the tail 38 of the knuckle 18 leading away from the throat 34 thereof is relieved, as shown in FIG. 1, from the contour of the corresponding knuckle inner side face portion 36' of a coupler having a standard 10A coupler contour. To this end, the inner side face portion 36 of the knuckle tail 38 may be contoured, as shown, along a shallow concave curve of relatively large radius, for example, around 5 inches or so radius, which joins at one end in a smooth continuous curve with the standard 10A contour 1% inch radius arcuate portion 54 of the knuckle throat 34 and at its other end joins with an angled tangent side face portion 56 which extends at an angle of about 40 to the longitudinal center line XX of the coupler when the knuckle 18 is locked in closed position in the coupler head 14. The extent of the relieving of the knuckle tail inner side face afforded by the shallow concavely curved contour portion 36, from the corresponding contour portion 36' of a standard 10A coupler contour, amounts to about threesixteenths inch at the mid-region of the curved portion 36.

Because of the relieving in accordance with the invention of the inner side face of the knuckle tail 38 to form the shallow curved contour wall portion 36, sufficient clearance is thereby provided for free withdrawal and disengagement from the coupler, during an uncoupling operation while its knuckle is locked in closed position, of an unlocked knuckle of an opposing mating coupler. Binding or grabbing of the knuckles of the mated couplers is thereby avoided during such an uncoupling operation, and proper uncoupling operation of the coupler under all conditions in service is consequently assured.

To enable couplers with the modified 10A contour 10 of the invention to meet the established vertical angling requirements of 3 57' forunseated couplers and 4 45 for couplers seated three thirty-seconds inch, for negotiating car dumper and classification humps, the front face 30 of the knuckle 18 is beveled at its top and bottom ends as shown at 58 and 58a, respectively, in FIG. 6, and the back or pulling face 42 of the knuckle is similarly beveled at its top and bottom ends as shown at 60 and 60a, respectively. For the purposes of the invention, these beveled surfaces 58, 58a and'60, 60a are tapered at an angle of about 4. In the case of the particular coupler illustrated which is the A.A.R. Type E coupler, the knuckle faces 30 and 42 of which both have a vertical extent of approximately 11 inches, the beveled surfaces 58, 58a and 60, 60a may extend for a distance of about 1% inches from the top and bottom of these faces.

Mated couplers having the modified 10A reduced slack contour 10 according to the invention and knuckles 18 with their front faces 30 and pulling faces 42 provided with the beveled ends 56, 56a and 58, 58a, respectively, have a vertical angling capability of up to 4 for unseated (new) couplers, and up to 4 45 for couplers after seated three thirty-seconds inch. Inasmuch as the vertical angling requirements for standard 10A contour couplers is 3 57' for unseated couplers and 4 45' after seated three thirty-seconds inch, the modified 10A contour coupler of the invention therefore fully meets these requirements. Likewise, a modified 10A contour coupler according to the invention coupled with a standard 10A contour coupler will provide up to 4 of vertical angling for unseated couplers and 4 50' after seated three thirty-seconds inch, both of which angling amounts exceed and therefore meet the corresponding requirements for standard 10A contour couplers. Although a modified 10A contour coupler according to the invention coupled to a standard Type F Interlocking coupler will provide only up to 3 of vertical angling as compared to 3 15' for a standard 10A bly greater vertical angling capability normally procontour coupler, this slight 15' lesser amount of vertical angling is of no consequence in this particular case vided for the Type E Interlocking coupler in its support mounting on the car. From the above, it will be evident that the modified 10A contour couplers according to the invention meet all the standard vertical angling requirements for the present standard 10A contour coupler both when coupled to each other as well as when coupled in interchange service with other standard type couplers. I

FIG. 5 illustrates how the relieving of the heel 32 and front face 30 of the knuckle 18 to form the compound curve contour portion 50 acts to increase the horizontal angle at which couplers having the tightened contour 10 according to the invention will couple together when the knuckle of only one of the couplers is in open position and the other coupler knuckle is locked in closed position. Because of the relieved front face portion 50 of the knuckle, the couplers are capable of coupling together with one another under the above mentioned conditions at horizontallyangled positions up to as much as 21 4 or thereabouts, as shown. This maximum horizontally angled coupling position is determined by that direction or line of entering travel of the open knuckle into the closed knuckle, as indicated by' the line M, which is tangent to the relieved compound curve front face portion 50 of the open knuckle at the point where it bears against the outer extremity point C of the guard arm inner side face 24of the closed cou pler. By comparison, if the opened knuckle 18 were not provided with the relieved compound curve front face contour portion50 in accordance with the invention, then such a knuckle on a coupler entering at the same 21% maximum horizontally angled coupling position of couplers comprising the invention would have to travel in a direction, as indicated by the line N in FIG.

5, which is tangent to the normal contoured front face, indicated in dotted lines at 50' in FIG. 5, of the opened knuckle at the point where it bears against the outer extremity point C of the guard' arm inner face 24. As shown, however, this line N of entering travel of such a contoured open knuckle would not be tangent to both of the convexly curved nose ends 44 of the two entering knuckles at the point where they bear against one another, with the result that these convex nose ends 44 would bind and interfere and thus prevent their passage past one another and into proper coupling position in the respective coupler pockets 62. Accordingly, the limiting horizontal angle at which a coupler of the tightened contour 10 but without the relieved knuckle front face and heel contour portion 50 will couple together witha coupler according to the invention having its knuckle in closed position will be some 5 or so less than the 21% maximum horizontally angled coupling position of couplers comprising the invention.

It will be apparent that the only modifications required to be made to couplers having standard 10A coupler contours in order to achieve the objects of the invention are confined entirely to the knuckle. Thus, by simply applying a modified knuckle 18 to an existing coupler head 14, the improvements afforded by the invention are immediately obtained. In this connection,

the modified knuckle 18 is applicable to all present standard E type coupler heads 14.

From the above description of the invention, it will be evident that a car coupler with materially reduced free slack as compared to that present in couplers with standard A coupler contours is thereby provided while at the same time maintaining the acceptable standard horizontal and vertical angling between couplers not only where it is coupled to another coupler according to the invention but also where it is coupled in interchange service with other type couplers having standard 10A coupler contours. Moreover, the reduction in coupler free slack provided by the invention is achieved while maintaining the same distance relationship between the front faces of the coupler knuckle and coupler head as that of the standard 10A coupler contour. Thus, a coupler according to the invention will properly match not only with another such coupler but also with all other type couplers having standard 10A coupler contours. As a result, the buffing forces applied to the matching couplers during buffing operations is applied to both sets of opposing knuckle and coupler head buffing interfaces to thereby distribute the buffing forces over both these engaged surfaces and so reduce the unit surface loading thereof to half that which would be applied in the case of unmatched couplers. Besides assuring the required horizontal. angling between mated couplers, the modified tightened 10A contour couplers according to the invention, both when coupled with each other as well as with couplers of various other 10A contours, also provide substantial interengaging bearing surfaces between the couplers both in pulled and buffed position as well as during horizontal angular displacement therebetween. This, in conjunction with its tightened contour 10, results inva coupler the rate of wear of which is reduced over that of couplers with standard 10A coupler contours and the worn limit life of which is therefore extended. Also, the added thickness of metal between the front and the pulling faces of the knuckle 18, over that present in the knuckle of a standard 10A contour coupler, imparts increased strength to the knuckle through the knuckle face.

The provision of the relieved inner side face contour portion 36 on the knuckle tail 32, in combination with the inwardly offset knuckle pulling face 42, the relieved knuckle heel and front face contour portion 50, and the beveled ends 58, 58a and 60, 60a on the knuckle buffing and pulling faces 30 and 42, not only results in a modified 10A contour coupler of tightened form having a materially reduced free slack of five-eighths inch amounting to a five sixty-fourths inch. or percent reduction in slack over the present standard 10A contour coupler, but also results in a coupler which is capable of performing all the normal service operations besides the required horizontal and vertical angling, and particularly an uncoupling operation where the knuckle of only one of the mated couplers is in unlocked position, the relieved knuckle tail inner side face portion 36 in such case affording sufficient clearance for free withdrawal and disengagement from the coupler of the unlocked knuckle of the opposing mating coupler.

It should be understood that the standard 10A coupler contour referred to in this specification and in the appended claims is that known as the American Association of Railroads (A.A.R.) standard No. 10A contour.

What is claimed is:

l. A car coupler having a tightened contour compared to a standard 10A coupler contour, said coupler comprising a coupler head having a standard 10A contour and a knuckle pivoted to said head, said knuckle comprising a nose portion having a front face and a pulling face, a heel portion, and a tail portion, said knuckle having a standard 10A contour so modified that the pulling face of said nose portion is located approximately five sixty-fourths inch closer to the buffing face of said head as measured along the longitudinal center line of the coupler and said heel portion and adjacent front face are relieved and contoured along a smooth compound convex curve formed by several radii, said modified contour providing a contour slack of approximately five-'eighths inch between two coupled couplers having heads with the standard 10A coupler contour and knuckles of said modified contour, as measured in a direction longitudinally of said couplers, while affording substantially the same amount of horizontal and vertical angling between the said coupled couplers as is present between two coupled couplers in which the heads and knuckles are of standard 10A contour. v

2. A car coupler as specified in claim 1 wherein the extent of relieving of the said heel portion and said adjacent front face of the knuckle provided by said compound curve contour amounts to about five sixtyfourths inch at the mid-region of said compound curve contour.

.3. A car coupler having a tightened contour compared to a standard 10A coupler contour, said coupler comprising a coupler head having a standard 10A contour and a knuckle pivoted to said head, said knuckle having a nose portion provided with a frontface' and a pulling face, a heel portion, a tail portion having a rearwardly extending side face and a throat portion joining said pulling face with said side face, and said knuckle having a standard 10A contour so modified that said pulling face is located approximately five sixty-fourths inch closer to the buffing face of said head as measured along the longitudinal center line of the coupler and said heel portion and said front face adjacent-thereto are relieved and contoured along a smooth compound convex curve formed by several radii, said modified contour providing a contour slack of approximately five-eighths inch between two coupled couplers having knuckles of said modified contour, as measured in a direction longitudinally of said couplers, while affording substantially the same amount of horizontal and vertical angling between the said coupled couplers as is present between two coupled couplers of standard 10A contour, said side face extending rearwardly from said throat portion and being relieved along a smooth concave curve of several inches radius extending into and joinedwith a side wall portion tangential therewith and disposed at an angle of about'40 to the longitudinal center line of the coupler with the knuckle locked in its closed position, said relieved side' face of the knuckle tail providing, during an uncoupling operation, clearance for free pivotal withdrawal from the coupler of an unlocked knuckle of an opposing mating coupler.

4. A car coupler as specified in claim 3 wherein the extent of relieving of the said heel portion and said adjacent front face of the knuckle provided bysaid compound curve contour amounts to about five sixtyfourths inch at the mid-region of said compound curve contour.

5. A car coupler as specified in claim 4 wherein the said concavely curved relieved section of said side face of the knuckle tail is formed by a radius of about 5 inches.

6. A car coupler as specified in claim 1 wherein the said compound convex curve forming the heel and adjacent front face contour portions of said knuckle is formed by successive radii of about 3 inches, inches, and 1% inches leading from the front face of said knuckle toward and around the heel thereof.

7. A car coupler knuckle for pivoted mounting on a coupler head having a standard 10A coupler contour, said knuckle comprising a hub portion and extending therefrom a heel portion, a nose portion, a tail portion, and a throat portion between said nose portion and tail portion, said knuckle having a 10A coupler contour modified to offset the pulling face of said nose portion approximately five sixty-fourths inch closer to the buffing face of the coupler head in which the knuckle is mounted, as measured along the longitudinal center line of the coupler and with the knuckle locked in its closed position in the head, and said heel portion and the adjacent front face of said knuckle being relieved and contoured along a smooth compound convex curve formed by several radii, said modified contour providing a contour slack of approximately five-eighths inch between two coupled couplers having standard 10A contour heads and knuckles of said modified contour.

8. A car coupler knuckle as specified in claim 7 wherein the extent of relieving of the said heel portion and the adjacent front face of the knuckle provided by said compound curve contour amounts to about five sixty-fourths inch at the mid-region of said compound curve contour.

9. A car coupler knuckle as specified in claim 7 I wherein said tail portion has a side face extending rearwardly from said throat portion and is relieved along a smooth concave curve of several inches radius extending into and joined with a side wall portion tangential therewith and disposed at an angle of about 40 to the longitudinal center line of the coupler head in the closed position of the knuckle mounted therein.

10. A car coupler knuckle as specified in claim 7 wherein the said compound convex curve forming said heel portion and said adjacent front face contour of said knuckle is formed by successive radii of about 3 inches, 10 inches, and 1% inches leading from the front face of said knuckle toward and around said heel portion thereof.

3 g UNITED STA 32s PATENT OFFICE CERTIFICATE OF CORRECTIQN Patent No. 3, 856, 156 Dated December 24, 1974 lnv willianl J. Metzger It is certified that error appears in the aboreidentified patent and that said Letters Patent are hereby corrected as shown below:

Column 9, line 47, "56,5621 and 58,58a" should be --58,5 8a and Column 10, 11118.3, "E "-should be --F--.-

Signed and sealed this 3rd day of June 1975.

(SEAL) Attes-t:

a c. MARSHALL DANN RUTH C. MASON, Commissioner of Patents Arresting Officer and Trademarks 

1. A car coupler having a tightened contour compared to a standard 10A coupler contour, said coupler comprising a coupler head having a standard 10A contour and a knuckle pivoted to said head, said knuckle comprising a nose portion having a front face and a pulling face, a heel portion, and a tail portion, said knuckle having a standard 10A contour so modified that the pulling face of said nose portion is located approximately five sixty-fourths inch closer to the buffing face of said head as measured along the longitudinal center line of the coupler and said heel portion and adjacent front face are relieved and contoured along a smooth compound convex curve formed by several radii, said modified contour providing a contour slack of approximately five-eighths inch between two coupled couplers having heads with the standard 10A coupler contour and knuckles of said modified contour, as measured in a direction longitudinally of said couplers, while affording substantially the same amount of horizontal and vertical angling between the said coupled couplers as is present between two coupled couplers in which the heads and knuckles are of standard 10A contour.
 2. A car coupler as specified in claim 1 wherein the extent of relieving of the said heel portion and said adjacent front face of the knuckle provided by said compound curve contour amounts to about five sixty-fourths inch at the mid-region of said compound curve contour.
 3. A car coupler having a tightened contour compared to a standard 10A coupler contour, said coupler comprising a coupler head having a standard 10A contour and a knuckle pivoted to said head, said knuckle having a nose portion provided with a front face and a pulling face, a heel portion, a tail portion having a rearwardly extending side face and a throat portion joining said pulling face with said side face, and said knuckle having a standard 10A contour so modified that said pulling face is located approximately five sixty-fourths inch closer to the buffing face of said head as measured along the longitudinal center line of the coupler and said heel portion and said front face adjacent thereto are relieved and contoured along a smooth compound convex curve formed by several radii, said modified contour providing a contour slack of approximately five-eighths inch between two coupled couplers having knuckles of said modified contour, as measured in a direction longitudinally of said couplers, while affording substantially the same amount of horizontal and vertical angling between the said coupled couplers as is present between two coupled couplers of standard 10A contour, said side face extending rearwardly from said throat portion and being relieved along a smooth concave curve of several inches radius extending into and joined with a side wall portion tangential therewith and disposed at an angle of about 40* to the longitudinal center line of the coupler with the knuckle locked in its closed position, said relieved side face of the knuckle tail providing, during an uncoupling operation, clearance for free pivotal withdrawal from the coupler of an unlocked knuckle of an opposing mating coupler.
 4. A car coupler as specified in claim 3 wherein the extent of relieving of the said heel portion and said adjacent front face of the knuckle provided by said compound curve contour amounts to about five sixty-fourths inch at the mid-region of said compound curve contour.
 5. A car coupler as specified in claim 4 wherein the said concavely curved relieved section of said side face of the knuckle tail is formed by a radius of about 5 inches.
 6. A car coupler as specified in claim 1 wherein the said compound convex curve forming the heel and adjacent front face contour portions of said knuckle is formed by successive radii of about 3 inches, 10 inches, and 1 1/4 inches leading from the front face of said knuckle toward and around the heel thereof.
 7. A car coupler knuckle for pIvoted mounting on a coupler head having a standard 10A coupler contour, said knuckle comprising a hub portion and extending therefrom a heel portion, a nose portion, a tail portion, and a throat portion between said nose portion and tail portion, said knuckle having a 10A coupler contour modified to offset the pulling face of said nose portion approximately five sixty-fourths inch closer to the buffing face of the coupler head in which the knuckle is mounted, as measured along the longitudinal center line of the coupler and with the knuckle locked in its closed position in the head, and said heel portion and the adjacent front face of said knuckle being relieved and contoured along a smooth compound convex curve formed by several radii, said modified contour providing a contour slack of approximately five-eighths inch between two coupled couplers having standard 10A contour heads and knuckles of said modified contour.
 8. A car coupler knuckle as specified in claim 7 wherein the extent of relieving of the said heel portion and the adjacent front face of the knuckle provided by said compound curve contour amounts to about five sixty-fourths inch at the mid-region of said compound curve contour.
 9. A car coupler knuckle as specified in claim 7 wherein said tail portion has a side face extending rearwardly from said throat portion and is relieved along a smooth concave curve of several inches radius extending into and joined with a side wall portion tangential therewith and disposed at an angle of about 40* to the longitudinal center line of the coupler head in the closed position of the knuckle mounted therein.
 10. A car coupler knuckle as specified in claim 7 wherein the said compound convex curve forming said heel portion and said adjacent front face contour of said knuckle is formed by successive radii of about 3 inches, 10 inches, and 1 1/4 inches leading from the front face of said knuckle toward and around said heel portion thereof. 